First of all, let me say that this is a well considered book. I haven't attended any seminars by John, but I have attended seminars by Iain Abertheny, and having read the book they are in the same ball-park: well considered views of the Heian katas with practical applications in mind.
First of all the book itself. It seems to have been published by B&W laser printer, meaning that the photographs - which ought to be in colour - are in B&W, and the low resolution printing does sometimes make it hard to see what exactly is going on.
The first thing I liked was John's choice to use the better translation of "receiver" for "uke" throughout. It is a better choice, but how refreshing to hear a shuto uke called a "knife hand receiver" rather than a "knife hand block"; after all, it makes the oyo more understandable once you think in those terms. If only our karate clubs were to do the same...
The text starts with the usual introduction to HAOV, though with some UK-centric statistics that are missing from the other works that I have seen in this style - specifically Iain Abernethy's "Bunkai Jutsu", and Kane and Wilder's "The Way of Kata. It then moves on to diagramming the vital points - without the detail of Ashley Croft's "Secret Karate" - before moving into application for each of the Heian katas.
The oyo given are, without a doubt, practical, sensible, and useful. There is no "he does that so you do that then he does this" about it; instead we have the heart of karate presented - the obtaining of advantage against an aggressor, and then the use of that advantage to kick the **** out of them, even if our initial attempts to kick the **** out if them fail.
All in all this has been an invaluable addition to my bookcase. Any book of application that can make you think again about the situations that are being referred to, and the programmed responses to those situations, is to be praised. John Titchen has produced an admirable work full of great ideas, and one that I will refer back to time after time. After the dark days of ridiculous bunkai, this is another invaluable addition to the library of any karateka who wants to know the point of their art. It is part of the modern movement of taking karate back to its real roots in practical hard core violence, and - along with the other books that I have mentioned - should be required reading for any serious study of the art.